SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5eb56d88908170d42da0a76487923b69551797d0bcae3d37badffc9858076fdd' 
  AND token = 'hHnDCNA9KDiXR+SqTuKJM+FwmB2yzghPyNhPn6+CL2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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