SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccd10c1f2fcdbca78a835f252d4871eea0e7c73d1abde37786657d36ff2f79e7' 
  AND token = 'XlNofMGuTvS9iy+8YUUKb9xfVdJ+zmOhjP8/FMgktvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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