SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '434047e1b847965124bafff1f8ae002f8cde8808854ff487697827d5cbde9565' 
  AND token = '/XFKSTX3c+FRHOW+slhy4qSAHKmBHSyqZ8mCyzDxVYQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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