SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0242871473d0c8c67dd88f35158582b05ef87797526d67153ba7bfaa63bca080' 
  AND token = 'ttTfR4UF81mv1U3EP9Y5xtkRYXy/Lc1f3mvfoVH+yL4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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