SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f64083f6a782595bab45ba649ad3739221ec2c9a474428b826a6ded19f77ca3b' 
  AND token = '4JRwEdQ+gO+5AZekbEsqZPjqTsJ5N4ybPUgNK2Vfttw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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