SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c4b85fdd0ed794e26f83deabd6e27f0b734913f209f87f8e3ad4735088df59ad' 
  AND token = 'o5enjwWEDjB+ifJxbuAyLLYsAvJ+1GfCGF5hjwEEs6Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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