SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee10437bef950d5796f894af97837c67f2323c13d23192d32d7b0860a2ec788c' 
  AND token = '8oNwUNH2v4fGbnW5SRjv5NM0LOefxKSowpFDbvbEveY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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