SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7114995b555af6f270e5d905af4bc7d0e26e92ba90f5f4f95a54b7f8f4b18379' 
  AND token = '272FOaKEqrJKZFTJJhomgtlm7nk0UWGnpwCWk+uhHMM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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