SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2abacd149954b8df48969ad1a603875304aea0fc3e3f5106190f4eb7938165e' 
  AND token = 'sVhLXGPeNf0+eLyBjvMyfutCqUXYkMlpI0kSBIcuWbE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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