SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a01b9f6e15219ababefef549faa54f797fbcc35560489f2187bf86b55524b57' 
  AND token = 'hncewqO9NZEn8boFvYr7+LHuy9cnYYtn8TlmIUXntpI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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