SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fd2d84f7e07b658f74a8b747f26c5225d1cb33439bda6798ad37a8db269c167' 
  AND token = 'IuGQTJp2a2oS+wYzv/Lpph1Qe3jxNNx9EEH+gnyLgOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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