SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9305cf06d673f9d5e9655d85f00b2b08fd5977ebb435baf096da35dbdc962ee9' 
  AND token = 'RObaZwJ8C/d1i0uc2XN23KNqmfzZ0FQ1LUsEEQd4QHg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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