SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff6326a20664311dc0043e68b5962ffa95749d130bc985221fb39cbe3e3f5171' 
  AND token = 'pC1YdN6Ua14AaJNmVNSAE8uTLZo78nQBTexIGAEWz1w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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