SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00271e82d522c3282a56ff4538be99aed2a8298ed4eac97f4f05347d99bfac09' 
  AND token = 'igFIDlmeAfHPcdmR0pXP/MkvW3bkpuHkB61qIilpeQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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