SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '432c181c62f3da05d0545ffba43964edf83fffeded2f847de150ca826419c848' 
  AND token = 'XZU89hSYCcZ1X9XW/pkWla6UJoBA87x32cpbOv8GFF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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