SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2494119dca674759a0972f961dd043b6d26bbcec827360fa9cd9293591a64b54' 
  AND token = 'cGFkzV940Uqr+LS0wEH6z3+FTjQyuFKZrFlBuNOFqzQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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