SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4aab1152a5a71e4eaee59bb4b0d053fc63988c711a6cee33b02f5af361b833f' 
  AND token = 'nEIvajrVVkw97Y81NSHX+khBuHXdgdzr1uaq1FdYA6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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