SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f46c0a0a6a7f27de3a472b5f1237d91afa9ff002d69485753c8fc3cedc82bcd' 
  AND token = 'EpuJGD6QLtJ9XeC3Gt4eM1SQUvy9m0BDKWVYt69oQAU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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