SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e91150aa1ded0dbcd9b0da2659679d538eb5227bdd504fded2b3ebfd6cc99d89' 
  AND token = 'h05fmlKk51FRauJbAxhLqU5LVP0X0wHQgBLJkXwASRE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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