SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7609020d1ce19153194142374e842c2f6eda13a2dd39c6168dd712f642e3e2c' 
  AND token = 'tJgCmFNNK9r/HRYZHNuDxPw2UtB+OUOwWufwWxnaz/A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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