SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5438739346cee733bdf0ed2422f665b589af5237ec0dbf4b874cf39b522e5bd6' 
  AND token = 'wLPoYjGDyUHK/Rrc/Il5HR8eQ/DiQQjQxwyB5XXmDYA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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