SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6cbd46634a690d4abac35a09ada626bd6fa83a0ec27423ee3c163140867cce5' 
  AND token = 'izzrR56e8C7w9QcoO5M/hzNb02IITTNnd+kqtvMCj1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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