SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c42be4aa760379b1aeb5f2f5199332b9adc01eb57234f559d545fc65975d0c6' 
  AND token = 'dWEnHimfp95BzVyHf/rH6d37usOcuvt7x13kzzJnzkU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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