SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '842385a0225b075002dd4bcf12c7638a14e87b9ffba14b12fc36febcb25a6d80' 
  AND token = 'WmGNHPUqlfW+MpKGdTCMXCpq5Q/ez6ro852zlWjpwpY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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