SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a451d14540af079caecb869e6cd4211293726909ecf41920316d5f9f21fdeeb' 
  AND token = 'LPhNPLBna+4svMr+KTGimNf6tVztFqyu32KLMJyzsSA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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