SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '73b408d64b86b995d48f2b28fa2a08858b694c9a26307c42c2fc958cb6a61849' 
  AND token = 'eJM07vGwF30Rit2Flk25riZdrsZRjHowQwqwksZiHSY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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