SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c12f0b830481d612ffd22d8fef0d5053caf9c3ce080001de36d510014854ac9a' 
  AND token = 'IPqyQWABxxIPMu8Q2TixI3FJCQb9rtmYdjVpKYPcSHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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