SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bce435c8efcc88c7499026160ec4a0ce41c643369769721d34928a32815f12b' 
  AND token = 'qFrwe9z7zBnzXFYJL4W+8x4PmEQVJjoJA1yb6Bzj8Sw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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