SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '704fe2fd474ebecfe82ab65d6bb7c3316d70b16d125137747b17e3ad8ca658fd' 
  AND token = 'LKP+YKaON2GiQuevP/6CoRNJgcgIj11SoOM6ravu2mE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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