SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b70a3cd97562b304b5ea656befe941b8f1649f039a913ac91e6ec995b54c37a' 
  AND token = 'FNvRfgeO27K+j83RSaQye6ah5gz3vqAnGakKY+N7q4w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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