SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47131def4468f0a0f6631eccfe88b65b1d54e876ff385a8dff01972643fcd480' 
  AND token = 'C+pcT4AqqMq6EvqBQFFHHBAk/tppTGxjXXVZncZtR+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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