SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a504841065ebabea38db23e31f7d7aa0a50361bb63c324ad4d1f098516bad7a' 
  AND token = 'uEgyLw3iUb8RdMdgZ7nCgIrCeDIX1xvziOHvFN/9qPI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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