SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d1456f56866e9b25e1a1aedb9d857d8e3649362ea86537b1472a42a0d251859' 
  AND token = 'HDme/JDSKMt13Ym5HLf9JsmOTGMELPz49AP6cei/H/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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