SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89f40115ad774a80a1bc0ae133b8b78abd521ffbe8291d9432b96ea78efd4efd' 
  AND token = 'USG20Pw4BrKOzJwSSWQJLTgJnupztN1GmWgbb0cMj+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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