SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64559e7a7596ef0f6c13c6ba48d21064d03425a1d470253bdb3ddf060f5ab31c' 
  AND token = 'lWtkcnFsVVRVMryEWF6Y2Nahtbw9QCh5L3wUGFMGmkk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00069

JSON explain

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