SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54517f60fc997493d10e256e8c32a26645766df3cf86794ed39f9e6be9697622' 
  AND token = 'p6mfcJus9ChSL+9Zq9fXNNGiUumaJx3RrYzcXS5r3C8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}