SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eec58486cd344d036b1c933aced837b9950f1d6ff0c88a45781042c0dd4a20ba' 
  AND token = 'f6UQD0Wr+o+2yrIdZRgviaYsGi/NuFALVJW1pVz4L68=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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