SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e156ef2bd0f3c965c71adde9cfccfba0cec82fbcfad2a537397395e74d5dc749' 
  AND token = 'crC1yblk4pUHSIdEqocZkYY6R0PeRmGEoYiZI7d0Slc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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