SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53e3a052fd977af65e30916f18238b6280d16bc9a443669a226b40cbde41de67' 
  AND token = 'aFwWn9Vco1F+i22F0j/FX4zYhVVRLfwO4VOgv/G+B78=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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