SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39b75d909059049de4a4dbaa045526ea87b111ddff0bd3b2f2532b969e8a1702' 
  AND token = 'IeSTQ/q4nTnoUVjXKuuadLSysVcexkFT6O4cBsRIkxw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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