SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a25ab1a48f1c3750dac3bc70129cb812109f966745323499dfdeabdb51d8146' 
  AND token = 'TrKvRGWSPF2kAvSyDjMikYmixywP+UaifwxIIGfgUHs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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