SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a3d559c2dcb2f7e5669bafffb4d52a60017919c6eba07851fcbff2d7f6467fe' 
  AND token = 'R9ExiSqdcr5kOWeLUHs3FvbC2Viq1JrFp5uBaGgeEpg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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