SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71796963ec2b99232dbd68e8b64df3ac377f36d6dcf52456c99047f995421efb' 
  AND token = 'OzNTHpD0/Sw22lo98u0M2YX+F+VKTZP2HLyshIXNLCc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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