SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5799989df628296e6e0096e88baa5a482100219c768ab07fdb76124eea9cd93' 
  AND token = 'VPgf7ajqxT9zffxKgU0/Oi29ViGv6FvLihPxcNcZXW0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}