SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '071c36e2f46ffa2647d34922d6ab37d0c410238fa3c14d5eeab5cd989a186210' 
  AND token = 'ksn+DnvQo3PEqOkyy+5qnxw0qGmFBvmFQSKLi8oVmGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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