SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9aa2426d52651fc0cc62c327a0795192a12a57add63f52da7d3f0cb1cfd62d29' 
  AND token = 'ZRk+0AWtf7vNBer+1/JMfNXX43VuQImJ8uie2cLnzzo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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