SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cbac8b2b49377c15707529dc7e14c03a7cfdc305df550f5c68ed4d3967258310' 
  AND token = 'SBCwDMzyXjZBmftT4p8l75T647GvzDqCvcbEaGLPHB8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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