SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '406d7f5899a81eb2b7b27cb2ded63492861b3c43b89cb9bb559143f7a5f915ab' 
  AND token = 'JepH7nw2N1AyVJPemGQTMsuOg1z3kuILFwY1ZhsKAig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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