SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea6bc558875a31723353da87898bd7f19262416ccf8982b1229697e1f83ef648' 
  AND token = 'wjLnAc6QK7tHUzVT2VwaszOgWX8VSjJNGGB+kcrFO4M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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