SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd874a9975f6f4233579c7a1636e1342e873cd3b3fcced5db805a450fe0b0576a' 
  AND token = 'UjUwXGiA4D4KDlUTwq2Cplx54P1L75uNPHfX1RTooS8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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