SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca57034a2279cfaae234def9c6fc7fcdb3f834d51e01d4261e9ae52f284ef43a' 
  AND token = 'bA5o0yWy6uyNADbX/KWKOiLmuTQ0/p8x4j7G+g8uw3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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