SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf38bffe50925192cdbe8823ce3346d1b5aa59c088be8448f6a196c3eaff7fcb' 
  AND token = 'ZhvoTdL6GgiMOpG14q24zq63FnQwjDmg0EpimMONE+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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