SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c356949a4ea19609cdd3e9ea3350535a6c7719c39ffeb5ec4dd6aacc73c50f2b' 
  AND token = 'DAC1GEt8+81QP+W0797kA/YrUbzicO2KkudIKFiYEYA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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