SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecc3097b7422693d202ca2b50eddaf72d5cf0a1da6fffe2aad6e6d068216f6d5' 
  AND token = 'cUfKzKm67vNM1UsUQ4ukOOC+lPgaaSLBGIYr69eInyc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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