SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19b9ea5639311a9336aedbc779e36c711612da579ab1a4ccd18b482577a19226' 
  AND token = 'RDILkSvZGiG6ITIUAHZ87xZLBmrE11sMSMEt7Ow4f+M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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