SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ee8626d2d54f50425cf0a65699c66a872c33432b09d9803c62417e9b1d9b8990' 
  AND token = 'vfxT7sgbzQkT3M8/PBhK67CZe/c9kS28jm6T1WzyN5s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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