SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39b06e6a0f90585553ac1b8d9a632d6980e54e39163982c970a6a2a67f8e82e7' 
  AND token = 'gRXbzo0A93d66uDihD73NV95hKq035zsKO1Ltv/d5F0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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