SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5aaff58f4c872f05cc78637455524fdbc27758dda673997677c67aa36e28be7e' 
  AND token = 'c55VYPGjzZ38ErodR2ow9CQrSwsdxresQ6M0XGoOVCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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