SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86c309c410ac9825ae679210d8d8f8eb058014ccbf21c6fadc1c1d126d2cdfe9' 
  AND token = 'kTLPCKmrPbZOqc4aVi1Pzg0W/VFDyXPh7AWqEAgCSL8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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