SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd00165deb6436f90235559198760b997396916e983fa86f2eba6674fb050e7e5' 
  AND token = 'elLnbdZYZiK+8XelWyuyWzFAH1VBV4oO09O/S1Rz3Co=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}